62.txt

;; [2] [[RFC 4234のABNF]] も参照。

;; [3] [[RFC 5234]] により[[廃止]]されています。

[1]  
[PRE[
diff -ub rfc2234.txt rfc4234.txt | modify
--- rfc2234.txt	1999-12-02 16:22:40.000000000 +0900
+++ rfc4234.txt	2005-10-04 03:29:51.000000000 +0900
@@ -5,16 +5,15 @@
 
 
 Network Working Group                                     D. Crocker, Ed.
-Request for Comments: 2234                       Internet Mail Consortium
-Category: Standards Track                                      P. Overell
-                                                      Demon Internet Ltd.
-                                                            November 1997
+Request for Comments: 4234                   Brandenburg InternetWorking
+Obsoletes: 2234                                               P. Overell
+Category: Standards Track                                      THUS plc.
+                                                            October 2005
 
 
              Augmented BNF for Syntax Specifications: ABNF
 
-
-Status of this Memo
+Status of This Memo
 
    This document specifies an Internet standards track protocol for the
    Internet community, and requests discussion and suggestions for
@@ -24,133 +23,168 @@
 
 Copyright Notice
 
-   Copyright (C) The Internet Society (1997).  All Rights Reserved.
+   Copyright (C) The Internet Society (2005).
+
+Abstract
+
+   Internet technical specifications often need to define a formal
+   syntax.  Over the years, a modified version of Backus-Naur Form
+   (BNF), called Augmented BNF (ABNF), has been popular among many
+   Internet specifications.  The current specification documents ABNF.
+   It balances compactness and simplicity, with reasonable
+   representational power.  The differences between standard BNF and
+   ABNF involve naming rules, repetition, alternatives, order-
+   independence, and value ranges.  This specification also supplies
+   additional rule definitions and encoding for a core lexical analyzer
+   of the type common to several Internet specifications.
 
-TABLE OF CONTENTS
+Table of Contents
 
-   1. INTRODUCTION ..................................................  2
 
-   2. RULE DEFINITION ...............................................  2
-   2.1 RULE NAMING ..................................................  2
-   2.2 RULE FORM ....................................................  3
-   2.3 TERMINAL VALUES ..............................................  3
-   2.4 EXTERNAL ENCODINGS ...........................................  5
-
-   3. OPERATORS .....................................................  5
-   3.1 CONCATENATION    RULE1     RULE2 .............................  5
-   3.2 ALTERNATIVES RULE1 / RULE2 ...................................  6
-   3.3 INCREMENTAL ALTERNATIVES   RULE1 =/ RULE2 ....................  6
-   3.4 VALUE RANGE ALTERNATIVES   %C##-## ...........................  7
-   3.5 SEQUENCE GROUP (RULE1 RULE2) .................................  7
-   3.6 VARIABLE REPETITION *RULE ....................................  8
-   3.7 SPECIFIC REPETITION NRULE ....................................  8
-   3.8 OPTIONAL SEQUENCE [RULE] .....................................  8
-   3.9 ; COMMENT ....................................................  8
-   3.10 OPERATOR PRECEDENCE .........................................  9
 
-   4. ABNF DEFINITION OF ABNF .......................................  9
 
-   5. SECURITY CONSIDERATIONS ....................................... 10
-   6. APPENDIX A - CORE ............................................. 11
-   6.1 CORE RULES ................................................... 11
-   6.2 COMMON ENCODING .............................................. 12
 
-   7. ACKNOWLEDGMENTS ............................................... 12
 
-   8. REFERENCES .................................................... 13
 
-   9. CONTACT ....................................................... 13
 
-   10. FULL COPYRIGHT STATEMENT ..................................... 14
+   1. INTRODUCTION ....................................................2
+   2. RULE DEFINITION .................................................3
+      2.1. Rule Naming ................................................3
+      2.2. Rule Form ..................................................3
+      2.3. Terminal Values ............................................4
+      2.4. External Encodings .........................................5
+   3. OPERATORS .......................................................6
+      3.1. Concatenation:  Rule1 Rule2 ................................6
+      3.2. Alternatives:  Rule1 / Rule2 ...............................6
+      3.3. Incremental Alternatives: Rule1 =/ Rule2 ...................7
+      3.4. Value Range Alternatives:  %c##-## .........................7
+      3.5. Sequence Group:  (Rule1 Rule2) .............................8
+      3.6. Variable Repetition:  *Rule ................................8
+      3.7. Specific Repetition:  nRule ................................9
+      3.8. Optional Sequence:  [RULE] .................................9
+      3.9. Comment:  ; Comment ........................................9
+      3.10. Operator Precedence .......................................9
+   4. ABNF DEFINITION OF ABNF ........................................10
+   5. SECURITY CONSIDERATIONS ........................................11
+   6. References .....................................................11
+      6.1. Normative References ......................................11
+      6.2. Informative References ....................................11
+   Appendix A.  ACKNOWLEDGEMENTS .....................................13
+   Appendix B.  APPENDIX - CORE ABNF OF ABNF .........................13
+      B.1.  Core Rules ...............................................13
+      B.2.  Common Encoding ..........................................14
 
 1.   INTRODUCTION
 
-   Internet technical specifications often need to define a format
+   Internet technical specifications often need to define a formal
    syntax and are free to employ whatever notation their authors deem
    useful.  Over the years, a modified version of Backus-Naur Form
    (BNF), called Augmented BNF (ABNF), has been popular among many
    Internet specifications.  It balances compactness and simplicity,
    with reasonable representational power.  In the early days of the
    Arpanet, each specification contained its own definition of ABNF.
-   This included the email specifications, RFC733 and then RFC822 which
-   have come to be the common citations for defining ABNF.  The current
-   document separates out that definition, to permit selective
-   reference.  Predictably, it also provides some modifications and
-   enhancements.
+   This included the email specifications, [RFC733] and then [RFC822],
+   which came to be the common citations for defining ABNF.  The current
+   document separates those definitions to permit selective reference.
+   Predictably, it also provides some modifications and enhancements.
 
    The differences between standard BNF and ABNF involve naming rules,
    repetition, alternatives, order-independence, and value ranges.
-   Appendix A (Core) supplies rule definitions and encoding for a core
-   lexical analyzer of the type common to several Internet
-   specifications.  It is provided as a convenience and is otherwise
-   separate from the meta language defined in the body of this document,
-   and separate from its formal status.
+   Appendix B supplies rule definitions and encoding for a core lexical
+   analyzer of the type common to several Internet specifications.  It
+   is provided as a convenience and is otherwise separate from the meta
+   language defined in the body of this document, and separate from its
+   formal status.
 
+   Changes since [RFC2234]:
 
+      In Section 3.7, the phrase: "That is, exactly <N> occurrences of
+      <element>." was corrected to: "That is, exactly <n> occurrences of
+      <element>."
+      Some continuation comment lines needed to be corrected to begin
+      with comment character (";").
 
 2.  RULE DEFINITION
 
-2.1  Rule Naming
+2.1.  Rule Naming
 
    The name of a rule is simply the name itself; that is, a sequence of
-   characters, beginning with  an alphabetic character, and followed by
+   characters, beginning with an alphabetic character, and followed by a
-   a combination of alphabetics, digits and hyphens (dashes).
+   combination of alphabetics, digits, and hyphens (dashes).
 
-        NOTE:     Rule names are case-insensitive
+   NOTE:
+      Rule names are case-insensitive
 
-   The names <rulename>, <Rulename>, <RULENAME> and <rUlENamE> all refer
-   to the same rule.
+   The names <rulename>, <Rulename>, <RULENAME>, and <rUlENamE> all
+   refer to the same rule.
 
    Unlike original BNF, angle brackets ("<", ">") are not  required.
    However, angle brackets may be used around a rule name whenever their
-   presence will facilitate discerning the use of  a rule name.  This is
+   presence facilitates in discerning the use of a rule name.  This is
    typically restricted to rule name references in free-form prose, or
    to distinguish partial rules that combine into a string not separated
    by white space, such as shown in the discussion about repetition,
    below.
 
-2.2  Rule Form
+2.2.  Rule Form
 
    A rule is defined by the following sequence:
 
         name =  elements crlf
 
    where <name> is the name of the rule, <elements> is one or more rule
-   names or terminal specifications and <crlf> is the end-of- line
-   indicator, carriage return followed by line feed.  The equal sign
+   names or terminal specifications, and <crlf> is the end-of-line
+   indicator (carriage return followed by line feed).  The equal sign
    separates the name from the definition of the rule.  The elements
    form a sequence of one or more rule names and/or value definitions,
-   combined according to the various operators, defined in this
-   document, such as alternative and repetition.
+   combined according to the various operators defined in this document,
+   such as alternative and repetition.
 
    For visual ease, rule definitions are left aligned.  When a rule
    requires multiple lines, the continuation lines are indented.  The
    left alignment and indentation are relative to the first lines of the
    ABNF rules and need not match the left margin of the document.
 
-2.3  Terminal Values
+2.3.  Terminal Values
 
    Rules resolve into a string of terminal values, sometimes called
-   characters.  In ABNF a character is merely a non-negative integer.
-   In certain contexts a specific mapping (encoding) of values into a
+   characters.  In ABNF, a character is merely a non-negative integer.
+   In certain contexts, a specific mapping (encoding) of values into a
    character set (such as ASCII) will be specified.
 
-   Terminals are specified by one or more numeric characters with the
+   Terminals are specified by one or more numeric characters, with the
    base interpretation of those characters indicated explicitly.  The
    following bases are currently defined:
 
@@ -160,18 +194,6 @@
 
         x           =  hexadecimal
 
    Hence:
 
         CR          =  %d13
@@ -182,21 +204,34 @@
    [US-ASCII] for carriage return.
 
    A concatenated string of such values is specified compactly, using a
-   period (".") to indicate separation of characters within that value.
-   Hence:
+   period (".") to indicate a separation of characters within that
+   value.  Hence:
 
         CRLF        =  %d13.10
 
-   ABNF permits specifying literal text string directly, enclosed in
-   quotation-marks.  Hence:
+   ABNF permits the specification of literal text strings directly,
+   enclosed in quotation-marks.  Hence:
 
         command     =  "command string"
 
    Literal text strings are interpreted as a concatenated set of
    printable characters.
 
-        NOTE:     ABNF strings are case-insensitive and
-                  the character set for these strings is us-ascii.
+   NOTE:
+
+      ABNF strings are case-insensitive and the character set for these
+      strings is us-ascii.
 
    Hence:
 
@@ -206,10 +241,11 @@
 
         rulename = "aBc"
 
-   will match "abc", "Abc", "aBc", "abC", "ABc", "aBC", "AbC" and "ABC".
+   will match "abc", "Abc", "aBc", "abC", "ABc", "aBC", "AbC", and
+   "ABC".
 
-                To specify a rule which IS case SENSITIVE,
-                   specify the characters individually.
+      To specify a rule that IS case SENSITIVE, specify the characters
+      individually.
 
    For example:
 
@@ -219,25 +255,16 @@
 
         rulename    =  %d97.98.99
 
-   will match only the string which comprises only lowercased
+   will match only the string that comprises only the lowercased
    characters, abc.
 
-2.4  External Encodings
+2.4.  External Encodings
 
    External representations of terminal value characters will vary
    according to constraints in the storage or transmission environment.
    Hence, the same ABNF-based grammar may have multiple external
    encodings, such as one for a 7-bit US-ASCII environment, another for
-   a binary octet environment and still a different one when 16-bit
+   a binary octet environment, and still a different one when 16-bit
    Unicode is used.  Encoding details are beyond the scope of ABNF,
    although Appendix A (Core) provides definitions for a 7-bit US-ASCII
    environment as has been common to much of the Internet.
@@ -245,13 +272,25 @@
    By separating external encoding from the syntax, it is intended that
    alternate encoding environments can be used for the same syntax.
 
 3.   OPERATORS
 
-3.1  Concatenation                                  Rule1 Rule2
+3.1.  Concatenation:  Rule1 Rule2
 
-   A rule can define a simple, ordered string of values -- i.e., a
-   concatenation of contiguous characters -- by listing a sequence of
-   rule names.  For example:
+   A rule can define a simple, ordered string of values (i.e., a
+   concatenation of contiguous characters) by listing a sequence of rule
+   names.  For example:
 
         foo         =  %x61           ; a
 
@@ -261,56 +300,61 @@
 
         So that the rule <mumble> matches the lowercase string "aba".
 
-        LINEAR WHITE SPACE:  Concatenation is at the core of the ABNF
-        parsing model.  A string of contiguous characters (values) is
-        parsed according to the rules defined in ABNF.  For Internet
-        specifications, there is some history of permitting linear white
-        space (space and horizontal tab) to be freelyPand
-        implicitlyPinterspersed around major constructs, such as
-        delimiting special characters or atomic strings.
+   LINEAR WHITE SPACE: Concatenation is at the core of the ABNF parsing
+   model.  A string of contiguous characters (values) is parsed
+   according to the rules defined in ABNF.  For Internet specifications,
+   there is some history of permitting linear white space (space and
+   horizontal tab) to be freely and implicitly interspersed around major
+   constructs, such as delimiting special characters or atomic strings.
-        NOTE:     This specification for ABNF does not
-                  provide for implicit specification of linear white
-                  space.
+   NOTE:
 
+      This specification for ABNF does not provide for implicit
+      specification of linear white space.
 
-   Any grammar which wishes to permit linear white space around
+   Any grammar that wishes to permit linear white space around
    delimiters or string segments must specify it explicitly.  It is
    often useful to provide for such white space in "core" rules that are
    then used variously among higher-level rules.  The "core" rules might
    be formed into a lexical analyzer or simply be part of the main
    ruleset.
 
-3.2  Alternatives                               Rule1 / Rule2
+3.2.  Alternatives:  Rule1 / Rule2
 
-   Elements separated by forward slash ("/") are alternatives.
+   Elements separated by a forward slash ("/") are alternatives.
    Therefore,
 
         foo / bar
 
    will accept <foo> or <bar>.
 
-        NOTE:     A quoted string containing alphabetic
-                  characters is special form for specifying alternative
-                  characters and is interpreted as a non-terminal
-                  representing the set of combinatorial strings with the
-                  contained characters, in the specified order but with
-                  any mixture of upper and lower case..
 
+   NOTE:
+
+      A quoted string containing alphabetic characters is a special form
+      for specifying alternative characters and is interpreted as a
+      non-terminal representing the set of combinatorial strings with
+      the contained characters, in the specified order but with any
+      mixture of upper and lower case.
-3.3  Incremental Alternatives                    Rule1 =/ Rule2
+3.3.  Incremental Alternatives: Rule1 =/ Rule2
 
    It is sometimes convenient to specify a list of alternatives in
    fragments.  That is, an initial rule may match one or more
    alternatives, with later rule definitions adding to the set of
-   alternatives.  This is particularly useful for otherwise- independent
-   specifications which derive from the same parent rule set, such as
+   alternatives.  This is particularly useful for otherwise, independent
+   specifications that derive from the same parent rule set, such as
    often occurs with parameter lists.  ABNF permits this incremental
    definition through the construct:
 
@@ -328,19 +372,7 @@
 
         ruleset     =  alt1 / alt2 / alt3 / alt4 / alt5
-3.4  Value Range Alternatives                           %c##-##
+3.4.  Value Range Alternatives:  %c##-##
 
    A range of alternative numeric values can be specified compactly,
    using dash ("-") to indicate the range of alternative values.  Hence:
@@ -353,50 +385,51 @@
 
                            "7" / "8" / "9"
 
-   Concatenated numeric values and numeric value ranges can not be
+   Concatenated numeric values and numeric value ranges cannot be
    specified in the same string.  A numeric value may use the dotted
    notation for concatenation or it may use the dash notation to specify
-   one value range.  Hence, to specify one printable character, between
+   one value range.  Hence, to specify one printable character between
    end of line sequences, the specification could be:
 
         char-line = %x0D.0A %x20-7E %x0D.0A
 
-3.5  Sequence Group                             (Rule1 Rule2)
+3.5.  Sequence Group:  (Rule1 Rule2)
 
    Elements enclosed in parentheses are treated as a single element,
    whose contents are STRICTLY ORDERED.   Thus,
 
         elem (foo / bar) blat
 
-   which matches (elem foo blat) or (elem bar blat).
+   matches (elem foo blat) or (elem bar blat), and
 
         elem foo / bar blat
 
    matches (elem foo) or (bar blat).
 
-        NOTE:     It is strongly advised to use grouping
-                  notation, rather than to rely on proper reading of
-                  "bare" alternations, when alternatives consist of
-                  multiple rule names or literals.
+   NOTE:
+
+      It is strongly advised that grouping notation be used, rather than
+      relying on the proper reading of "bare" alternations, when
+      alternatives consist of multiple rule names or literals.
 
-   Hence it is recommended that instead of the above form, the form:
+   Hence, it is recommended that the following form be used:
 
         (elem foo) / (bar blat)
 
-   be used.  It will avoid misinterpretation by casual readers.
+   It will avoid misinterpretation by casual readers.
 
    The sequence group notation is also used within free text to set off
    an element sequence from the prose.
-3.6  Variable Repetition                                *Rule
+3.6.  Variable Repetition:  *Rule
 
    The operator "*" preceding an element indicates repetition. The full
    form is:
@@ -404,13 +437,22 @@
         <a>*<b>element
 
    where <a> and <b> are optional decimal values, indicating at least
-   <a> and at most <b> occurrences of element.
+   <a> and at most <b> occurrences of the element.
 
    Default values are 0 and infinity so that *<element> allows any
    number, including zero; 1*<element> requires at  least  one;
    3*3<element> allows exactly 3 and 1*2<element> allows one or two.
 
-3.7  Specific Repetition                                  nRule
+3.7.  Specific Repetition:  nRule
 
    A rule of the form:
 
@@ -420,11 +462,10 @@
 
         <n>*<n>element
 
-   That is, exactly  <N>  occurrences  of <element>. Thus 2DIGIT is a
-   2-digit number, and 3ALPHA is a string of three alphabetic
-   characters.
+   That is, exactly <n> occurrences of <element>.  Thus, 2DIGIT is a 2-
+   digit number, and 3ALPHA is a string of three alphabetic characters.
 
-3.8  Optional Sequence                                   [RULE]
+3.8.  Optional Sequence:  [RULE]
 
    Square brackets enclose an optional element sequence:
 
@@ -434,47 +475,55 @@
 
         *1(foo bar).
 
-3.9  ; Comment
+3.9.  Comment:  ; Comment
 
    A semi-colon starts a comment that continues to the end of line.
    This is a simple way of including useful notes in parallel with the
    specifications.
 
-3.10 Operator Precedence
+3.10.  Operator Precedence
 
    The various mechanisms described above have the following precedence,
-   from highest (binding tightest) at the top, to lowest and loosest at
+   from highest (binding tightest) at the top, to lowest (loosest) at
    the bottom:
 
-        Strings, Names formation
-        Comment
-        Value range
-        Repetition
-        Grouping, Optional
-        Concatenation
-        Alternative
+         Strings, Names formation
 
+         Comment
 
+         Value range
 
+         Repetition
 
+         Grouping, Optional
 
+         Concatenation
+         Alternative
-   Use of the alternative operator, freely mixed with concatenations can
-   be confusing.
+   Use of the alternative operator, freely mixed with concatenations,
+   can be confusing.
 
         Again, it is recommended that the grouping operator be used to
         make explicit concatenation groups.
 
 4.   ABNF DEFINITION OF ABNF
 
+   NOTES:
+
+      1. This syntax requires a formatting of rules that is relatively
+         strict.  Hence, the version of a ruleset included in a
+         specification might need preprocessing to ensure that it can be
+         interpreted by an ABNF parser.
+
-   This syntax uses the rules provided in Appendix A (Core).
+      2. This syntax uses the rules provided in Appendix B (Core).
 
         rulelist       =  1*( rule / (*c-wsp c-nl) )
 
@@ -500,19 +549,20 @@
         alternation    =  concatenation
                           *(*c-wsp "/" *c-wsp concatenation)
 
          concatenation  =  repetition *(1*c-wsp repetition)
          repetition     =  [repeat] element
 
          repeat         =  1*DIGIT / (*DIGIT "*" *DIGIT)
         element        =  rulename / group / option /
                           char-val / num-val / prose-val
@@ -523,7 +573,7 @@
 
         char-val       =  DQUOTE *(%x20-21 / %x23-7E) DQUOTE
                                ; quoted string of SP and VCHAR
-                                  without DQUOTE
+                                ;  without DQUOTE
 
         num-val        =  "%" (bin-val / dec-val / hex-val)
 
@@ -540,15 +590,69 @@
 
         prose-val      =  "<" *(%x20-3D / %x3F-7E) ">"
                                ; bracketed string of SP and VCHAR
-                                  without angles
+                                ;  without angles
                                ; prose description, to be used as
-                                  last resort
+                                ;  last resort
 
 5.   SECURITY CONSIDERATIONS
 
    Security is truly believed to be irrelevant to this document.
 
+6.  References
+
+6.1.  Normative References
+
+   [US-ASCII] American National Standards Institute, "Coded Character
+              Set -- 7-bit American Standard Code for Information
+              Interchange", ANSI X3.4, 1986.
+
+6.2.  Informative References
+
+   [RFC2234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
+              Specifications: ABNF", RFC 2234, November 1997.
+
+   [RFC733]   Crocker, D., Vittal, J., Pogran, K., and D. Henderson,
+              "Standard for the format of ARPA network text messages",
+              RFC 733, November 1977.
+
+   [RFC822]   Crocker, D., "Standard for the format of ARPA Internet
+              text messages", STD 11, RFC 822, August 1982.
 
@@ -559,20 +663,57 @@
 
+Appendix A.  ACKNOWLEDGEMENTS
+
+   The syntax for ABNF was originally specified in RFC 733.  Ken L.
+   Harrenstien, of SRI International, was responsible for re-coding the
+   BNF into an augmented BNF that makes the representation smaller and
+   easier to understand.
+
+   This recent project began as a simple effort to cull out the portion
+   of RFC 822 that has been repeatedly cited by non-email specification
+   writers, namely the description of augmented BNF.  Rather than simply
+   and blindly converting the existing text into a separate document,
+   the working group chose to give careful consideration to the
+   deficiencies, as well as benefits, of the existing specification and
+   related specifications made available over the last 15 years, and
+   therefore to pursue enhancement.  This turned the project into
+   something rather more ambitious than was first intended.
+   Interestingly, the result is not massively different from that
+   original, although decisions, such as removing the list notation,
+   came as a surprise.
+
+   This "separated" version of the specification was part of the DRUMS
+   working group, with significant contributions from Jerome Abela,
+   Harald Alvestrand, Robert Elz, Roger Fajman, Aviva Garrett, Tom
+   Harsch, Dan Kohn, Bill McQuillan, Keith Moore, Chris Newman, Pete
+   Resnick, and Henning Schulzrinne.
+
+   Julian Reschke warrants a special thanks for converting the Draft
+   Standard version to XML source form.
+
-6.   APPENDIX A - CORE
+Appendix B.  APPENDIX - CORE ABNF OF ABNF
 
    This Appendix is provided as a convenient core for specific grammars.
    The definitions may be used as a core set of rules.
 
-6.1  Core Rules
+B.1.  Core Rules
 
-   Certain  basic  rules  are  in uppercase, such as SP, HTAB, CRLF,
-   DIGIT, ALPHA, etc.
+   Certain basic rules are in uppercase, such as SP, HTAB, CRLF, DIGIT,
+   ALPHA, etc.
 
         ALPHA          =  %x41-5A / %x61-7A   ; A-Z / a-z
 
@@ -580,7 +721,16 @@
 
         CHAR           =  %x01-7F
                                ; any 7-bit US-ASCII character,
-                                  excluding NUL
+                                ;  excluding NUL
 
         CR             =  %x0D
                                ; carriage return
@@ -613,54 +763,19 @@
 
         SP             =  %x20
-                               ; space
         VCHAR          =  %x21-7E
                                ; visible (printing) characters
 
         WSP            =  SP / HTAB
                                ; white space
 
-6.2  Common Encoding
+B.2.  Common Encoding
 
-   Externally, data are represented as "network virtual ASCII", namely
-   7-bit US-ASCII in an 8-bit field, with the high (8th) bit set to
-   zero.  A string of values is in "network byte order" with the
-   higher-valued bytes represented on the left-hand side and being sent
-   over the network first.
+   Externally, data are represented as "network virtual ASCII" (namely,
+   7-bit US-ASCII in an 8-bit field), with the high (8th) bit set to
+   zero.  A string of values is in "network byte order", in which the
+   higher-valued bytes are represented on the left-hand side and are
+   sent over the network first.
-7.   ACKNOWLEDGMENTS
-
-   The syntax for ABNF was originally specified in RFC 733.  Ken L.
-   Harrenstien, of SRI International, was responsible for re-coding the
-   BNF into an augmented BNF that makes the representation smaller and
-   easier to understand.
-
-   This recent project began as a simple effort to cull out the portion
-   of RFC 822 which has been repeatedly cited by non-email specification
-   writers, namely the description of augmented BNF.  Rather than simply
-   and blindly converting the existing text into a separate document,
-   the working group chose to give careful consideration to the
-   deficiencies, as well as benefits, of the existing specification and
-   related specifications available over the last 15 years and therefore
-   to pursue enhancement.  This turned the project into something rather
-   more ambitious than first intended.  Interestingly the result is not
-   massively different from that original, although decisions such as
-   removing the list notation came as a surprise.
-
-   The current round of specification was part of the DRUMS working
-   group, with significant contributions from Jerome Abela , Harald
-   Alvestrand, Robert Elz, Roger Fajman, Aviva Garrett, Tom Harsch, Dan
-   Kohn, Bill McQuillan, Keith Moore, Chris Newman , Pete Resnick and
-   Henning Schulzrinne.
 
@@ -668,39 +783,32 @@
-8.   REFERENCES
-
-   [US-ASCII]     Coded Character Set--7-Bit American Standard Code for
-   Information Interchange, ANSI X3.4-1986.
-
-   [RFC733]  Crocker, D., Vittal, J., Pogran, K., and D. Henderson,
-   "Standard for the Format of ARPA Network Text Message," RFC 733,
-   November 1977.
 
-   [RFC822]  Crocker, D., "Standard for the Format of ARPA Internet Text
-   Messages", STD 11, RFC 822, August 1982.
-9.   CONTACT
+Authors' Addresses
 
-   David H. Crocker                 Paul Overell
 
-   Internet Mail Consortium         Demon Internet Ltd
-   675 Spruce Dr.                   Dorking Business Park
-   Sunnyvale, CA 94086 USA          Dorking
-                                    Surrey, RH4 1HN
                                     UK
 
-   Phone:    +1 408 246 8253
-   Fax:      +1 408 249 6205
-   EMail:    dcrocker@imc.org       paulo@turnpike.com
+   Dave Crocker (editor)
+   Brandenburg InternetWorking
+   675 Spruce Dr.
+   Sunnyvale, CA  94086
+   US
 
+   Phone: +1.408.246.8253
+   EMail: dcrocker@bbiw.net
+   Paul Overell
+   THUS plc.
+   1/2 Berkeley Square
+   99 Berkeley Street
+   Glasgow
+   G3 7HR
+   EMail: paul.overell@thus.net
@@ -727,52 +835,59 @@
-10.  Full Copyright Statement
+Full Copyright Statement
 
-   Copyright (C) The Internet Society (1997).  All Rights Reserved.
+   Copyright (C) The Internet Society (2005).
 
-   This document and translations of it may be copied and furnished to
-   others, and derivative works that comment on or otherwise explain it
-   or assist in its implementation may be prepared, copied, published
-   and distributed, in whole or in part, without restriction of any
-   kind, provided that the above copyright notice and this paragraph are
-   included on all such copies and derivative works.  However, this
-   document itself may not be modified in any way, such as by removing
-   the copyright notice or references to the Internet Society or other
-   Internet organizations, except as needed for the purpose of
-   developing Internet standards in which case the procedures for
-   copyrights defined in the Internet Standards process must be
-   followed, or as required to translate it into languages other than
-   English.
+   This document is subject to the rights, licenses and restrictions
+   contained in BCP 78, and except as set forth therein, the authors
+   retain all their rights.
-   The limited permissions granted above are perpetual and will not be
-   revoked by the Internet Society or its successors or assigns.
-
-   This document and the information contained herein is provided on an
-   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
-   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
-   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
-   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
-   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+   This document and the information contained herein are provided on an
+   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
+   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
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+   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
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+   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 
+Intellectual Property
 
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+   http://www.ietf.org/ipr.
 
+   The IETF invites any interested party to bring to its attention any
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+   this standard.  Please address the information to the IETF at ietf-
+   ipr@ietf.org.
 
+Acknowledgement
 
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
]PRE]